1. Field of the Invention
The invention relates to a speed control system and, in particular, to a current and velocity sensing speed control system using current and velocity sensing on board a model electric train locomotive engine.
2. Description of the Related Art
In electric model toy trains, as in actual trains, a locomotive engine typically pulls a consist, which is the full set of cars which make up a train. The setup typically includes a user control box electrically connected to one or more of the train track rails having one or more levers, dials, or buttons that are manually adjustable by the user. The control box enables the user to control the speed and direction of the electric train by manually controlling the voltage levels supplied to the electronic systems and motor of the locomotive. However, only limited speed control is incorporated into the on-board control system and motor.
One problem with existing speed control systems arises when the user changes the setting of, and thus the voltage supplied to, the locomotive to speed it up or slow it down. With limited speed control, it is difficult for the user to finely control the speed of the electric train. Another problem occurs as a result of fluctuations or spikes in the electrical supply. These spikes can result in undesired increases or decreases in the speed of the electric train that occasionally lead to train derailments, especially on curved sections of track when a train is traveling at faster speeds.
Further, difficulties occur when coupling two or more locomotives together, so-called “lashup,” and when one or more locomotives are added to the middle or end of a consist. Although each locomotive draws on a common electrical supply, each can run at a slightly different speed than the other(s). When the speed is not constant between locomotives, the locomotives can fight each other.